Correction of astigmatism on the thin cornea with the femtosecond laser

Abstract

Purpose: to examine the efficacy and safety of arcuate incisions using a femtosecond laser for the treatment of astigmatism at patient with a thin cornea.
Methods: this retrospective study included 10 eyes of 6 patients after astigmatical keratotomy (AK). Preoperatively and 1, 3, 6 months after surgery, a full ophthalmic examination was performed. AK was done using the Femtec 520F fs laser system (technolas Perfect Vision). Pre- and postoperative complete ophthalmic examination including uncorrected and best spectacle corrected visual acuity, corneal topogra- phy Zyotix (Bausch&Lomb), OCt (Optovue) was done.
Results: Mean preoperative astigmatism was 3.75±0.51 D, thickness was 470 ± 26 μm, BCVA was 0.74 ± 0.12. At all patients the high visual acuity, corresponding the maximal visual acuity with correction before operation has been achieved. three months after surgery UCVA was 0.65±0.25, BSCVA was 0.85±0.15 with –0.55±0.25 D SE. Postoperative subjective manifest cylinder was mean –0.75±0.5 D, topographic astigmatism was mean 1.25±0.5 D. Full neutralisation corneal astigmatism is reached in 70%. No intraoperative or postoperative adverse events were seen during the follow-up period.
Conclusion: thus, spending АК cuts with precision accuracy on depth, the form and length by FS laser, we considerably reduce risk of operational complications. Also substantially we raise clinical accuracy, safety and efficiency of the given method in correction corneal astigmatism, in comparison with classical tangential keratotomy. In clinical situations when the thickness of a cornea does not allow to spend safely and effectively excimer laser ablation the given technology is, as a matter of fact, a unique variant of possible correction astigmatism.